Generally, in electronic circuit boards such as printed circuit boards (PCBs) and a press-fit connector has been widely used for connecting terminals.
The press-fit connector connects connector leads into through-holes of the electronic circuit board by press-fitting. Here, the through-hole is formed on the electronic circuit board, and an inner wall of the hole is coated with a conductive metal material so as to form a conductive hole.
Soldering defects may occur generally in the case where the number of leads is high and a distance between leads is narrow, such that, the press-fit connector having the leads which are fixedly connected into through-holes, respectively, is used.
The press-fit connector has the advantages of having a simple connection process, causing no thermal damage on the PCBs and the device parts, requiring no soldering bridge, and consuming less energy because there is no soldering process with respect to leads.
FIG. 1 is a cross-sectional view showing how a press-fit connector is connected to an electronic circuit board such as a PCB. Reference numeral 11 denotes a connector housing and reference numeral 12 denotes a connector lead for the connection with an electronic circuit board 20.
Further, reference numeral 21 denotes a plastic substrate of the electronic circuit board 20, and reference numeral 22 denotes a circuit pattern of the electronic circuit board 20.
As shown in the figure, the connector lead 12 is provided with a wedge portion 13 whose diameter is larger than an inner diameter of a through-hole 24 so that the connector lead 12 is fixedly press-fitted into the through-hole 24 of the circuit board 20 by the connection of the wedge portion 13 with the through-hole 24.
However, the related art has problems in that a coating layer 23 on the inner wall of the through-hole 24 in the circuit board 20 is subjected to damage because of a press-fitting action of the lead 12, and therefore, due to such a risk of the coating layer being damaged, the fastening force cannot be regulated to a specified level or more, resulting in the fastening force becoming weaker.
Particularly, when a press-fitting connector is adapted to a high-voltage specification of an electric vehicle (EV) or a hybrid vehicle, there may be a problem of heating due to degradation of the fastening force.